Abstract:  We discuss the existence and the number of periodic solutions of differential equation dx/dt=A₁（t）x+A₂（t）x²+A₃（t）x³/a₀（t）+a₁（t）x+a₂（t）x² （1）where A_i（t）, a_j（t） （i=1,2,3;j=0,1,2） are continuous periodic functions. The results of this paper extend the work of paper [1].

Key words:  , periodic solution, strip domain, stability, transformation